Various information processing systems have been developed as a result of the rapid development which have taken place in the information industry in recent years. Methods of recording and apparatus compatible with these information processing systems have been developed and adopted. Thermal transfer recording methods, i.e., recording methods of this type, involve the use of, an apparatus which is light and compact, with which there is little noise, and which has excellent operability and maintenance characteristics. Moreover, since they also allow coloring to be achieved easily, these methods are the most widely used. Thermal transfer recording methods can be broadly classified into two types, namely thermofusion types and thermomobile types. In the latter case, a thermal transfer dye donating material which has, on a support, a dye donating layer which contains a binder and a thermomobile dye is laminated with a thermal transfer image receiving material, heat is applied from the support side of the dye donating material, the thermomobile dye is transferred to the recording medium (thermal transfer image receiving material) in the form of a pattern corresponding to the heat pattern which has been applied and an image is formed in this way.
Moreover, a thermomobile dye is, for example, a dye which can be transferred from a thermal transfer dye donating material to a thermal transfer image receiving material by sublimation or diffusion in a medium.
However, the following disadvantages are encountered with thermal transfer image receiving materials in which the thermomobile type thermal transfer recording method is employed.
(1) The polymers used in the receiving layer for the thermomobile dye are soluble in organic solvents and so an organic solvent system is used for the receiving layer coating liquid. Furthermore, the apparatus and vessels used in the manufacturing process must be cleaned with organic solvents. Hence, the apparatus used for preparing the coating liquid and the coating apparatus must be explosion-proof. Furthermore, organic solvents are very expensive when compared to water and so the production costs are increased. Moreover problems can arise with the health supervision of the operators. PA1 (2) Polymers which soften or become rubber-like during thermal transfer are sometimes used as binders for receiving layers, or plasticizers may be used, in order to achieve high density images However, irregularities are produced at the transfer surface in the maximum density regions when these devices are used and this results in a loss of gloss. Moreover, the image tends to fade on long term storage of the thermal transfer image receiving material after a transfer has been made.
Furthermore, JP-A-57-137191 or JP-A-60-38192 (the term "JP-A" as used herein means an "unexamined published Japanese patent application) describes a thermal transfer image receiving material which is produced by coating on a support a mixture of latexes of a saturated polyester or a vinyl-series polymer with a water soluble binder such as hydroxyethyl cellulose. However, the above-mentioned publications do not describe the formation of bridge at the binder portion such as hydroxyethyl cellulose at all. The thermal transfer image receiving material as described in the publications is heat fused with a dye donating material in case of thermally transferring a dye. Further, the dye image having been formed on the image receiving material as described in the publications is apt to be re-transferred onto the other substances, or the mechanical strength of a layer on the image receiving material, on which the image has been formed is apt to decrease in the presence of water or moisture.